hdu1151 Air Raid 基础匈牙利

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
using namespace std;

#define MAXN 150
int n;    //十字路口的数量
int m;    //路的个数
int map[MAXN][MAXN];
int x[MAXN], y[MAXN];
int mark[MAXN];

int search(int a)
{
    for (int i = 1; i <= n; i++)
    {
        if (map[a][i] && !mark[i])
        {
            mark[i] = 1;
            if (y[i] == 0 || search(y[i]))
            {
                x[a] = i;
                y[i] = a;
                return a;
            }
        }
    }
    return 0;
}

int main()
{
    int t;
    scanf("%d", &t);
    while (t--)
    {
        memset(map, 0, sizeof(map));
        memset(mark, 0, sizeof(mark));
        scanf("%d %d", &n, &m);
        for (int i = 0; i < m; i++)
        {
            int a, b;
            scanf("%d %d", &a, &b);
            if (map[a][b] == 0)
                map[a][b] = 1;
        }

        int ans1 = 0;
        memset(x, 0, sizeof(x));
        memset(y, 0, sizeof(y));

        for (int i = 1; i <= n; i++)
        {
            if (x[i] == 0)
            {
                memset(mark, 0, sizeof(mark));
                if (search(i))
                    ans1++;
            }
        }
        printf("%d
", n - ans1);
    }
    //system("pause");
    return 0;
}